/* Generated By:JavaCC: Do not edit this line. CharStream.java Version 4.0 */

package sidekick.css.parser;



/**

 * This interface describes a character stream that maintains line and

 * column number positions of the characters.  It also has the capability

 * to backup the stream to some extent.  An implementation of this

 * interface is used in the TokenManager implementation generated by

 * JavaCCParser.

 *

 * All the methods except backup can be implemented in any fashion. backup

 * needs to be implemented correctly for the correct operation of the lexer.

 * Rest of the methods are all used to get information like line number,

 * column number and the String that constitutes a token and are not used

 * by the lexer. Hence their implementation won't affect the generated lexer's

 * operation.

 */



public interface CharStream {



  /**

   * Returns the next character from the selected input.  The method

   * of selecting the input is the responsibility of the class

   * implementing this interface.  Can throw any java.io.IOException.

   */

  char readChar() throws java.io.IOException;



  /**

   * Returns the column position of the character last read.

   * @deprecated 

   * @see #getEndColumn

   */

  int getColumn();



  /**

   * Returns the line number of the character last read.

   * @deprecated 

   * @see #getEndLine

   */

  int getLine();



  /**

   * Returns the column number of the last character for current token (being

   * matched after the last call to BeginTOken).

   */

  int getEndColumn();



  /**

   * Returns the line number of the last character for current token (being

   * matched after the last call to BeginTOken).

   */

  int getEndLine();



  /**

   * Returns the column number of the first character for current token (being

   * matched after the last call to BeginTOken).

   */

  int getBeginColumn();



  /**

   * Returns the line number of the first character for current token (being

   * matched after the last call to BeginTOken).

   */

  int getBeginLine();



  /**

   * Backs up the input stream by amount steps. Lexer calls this method if it

   * had already read some characters, but could not use them to match a

   * (longer) token. So, they will be used again as the prefix of the next

   * token and it is the implemetation's responsibility to do this right.

   */

  void backup(int amount);



  /**

   * Returns the next character that marks the beginning of the next token.

   * All characters must remain in the buffer between two successive calls

   * to this method to implement backup correctly.

   */

  char BeginToken() throws java.io.IOException;



  /**

   * Returns a string made up of characters from the marked token beginning 

   * to the current buffer position. Implementations have the choice of returning

   * anything that they want to. For example, for efficiency, one might decide

   * to just return null, which is a valid implementation.

   */

  String GetImage();



  /**

   * Returns an array of characters that make up the suffix of length 'len' for

   * the currently matched token. This is used to build up the matched string

   * for use in actions in the case of MORE. A simple and inefficient

   * implementation of this is as follows :

   *

   *   {

   *      String t = GetImage();

   *      return t.substring(t.length() - len, t.length()).toCharArray();

   *   }

   */

  char[] GetSuffix(int len);



  /**

   * The lexer calls this function to indicate that it is done with the stream

   * and hence implementations can free any resources held by this class.

   * Again, the body of this function can be just empty and it will not

   * affect the lexer's operation.

   */

  void Done();



}